| dc.description.abstract | Kelapa sawit merupakan salah satu komoditas penting dalam perekonomian
Indonesia dari sektor non migas tetapi dominan dibudi dayakan pada lahan mineral
masam yang cekaman alumunium (Al) menjadi salah satu pembatas utama.
Cekaman Al menghambat pertumbuhan dan perkembangan tanaman sehingga
produksi dibawah potensinya dan upaya perbaikan diperlukan. Berbagai senyawa
eksogen telah dilaporkan mampu mengurangi toksisitas Al seperti kalsium, asam
sitrat, asam salisilat, hormon dan osmoprotektan. Penelitian ini bertujuan
memperoleh teknik budi daya guna meningkatkan produktivitas dan rendemen
kelapa sawit melalui pemberian senyawa eksogen pada lahan masam dengan
kandungan Al tinggi. Penelitian ini terdiri dari tiga percobaan yang dilakukan di
areal perkebunan PT Astra Agro Lestari, Tbk.
Percobaan 1 dilaksanakan di rumah kaca di PT Gunung Sejahtera Ibu Pertiwi,
Kalimantan Tengah dari bulan September 2018 sampai April 2019. Bibit kelapa
sawit umur 10 minggu setelah tanam dipindahkan ke sistem hidroponik dalam
media kultur hara. Percobaan ini terdiri dari dua sub Percobaan yaitu percobaan
toksisitas Al dan pengaruh berbagai senyawa eksogen terhadap induksi toleransi
cekaman Al. Peubah yang diamati adalah kadar malondialdehid (MDA), aktivitas
enzim katalase (CAT) dan ascorbat peroksidase (APX), laju fotosintesis, dan
pertumbuhan vegetatif. Sub percobaan 1.1 toksisitas Al menggunakan berbagai
konsentrasi Al seperti 0, 100, 200, 400, 800 dan 1600 µM. Perlakuan Al lebih dari
400 µM signifikan menurunkan panjang akar, bobot kering akar dan tajuk, laju
fotosintesis, aktivitas enzim CAT dan APX disertai peningkatan kadar MDA.
Hambatan pertumbuhan pada 400 µM Al terlihat pada panjang akar mencapai
33,9%, bobot kering akar 32,75% dan bobot kering tajuk 46,78%. Berdasarkan hasil
tersebut, konsentrasi 400 µM Al dapat digunakan dalam seleksi varietas kelapa
sawit toleran Al.
Sub percobaan 1.2 pengaruh berbagai senyawa eksogen terhadap induksi
toleransi cekaman Al menggunakan berbagai konsentrasi kalsium, asam sitrat,
ethepon dan air gambut pada media kultur hara yang mengandung 400 µM Al.
Konsentrasi kalsium, asam sitrat dan ethepon yang ditambahkan adalah 0, 25, 50
dan 100 ppm sedangkan air gambut adalah 0, 100, 200 dan 300 ppm. Penambahan
kalsium, asam sitrat dan air gambut mampu memperbaiki pertumbuhan tanaman
yang tercekam Al, sedangkan penambahan ethepon justru meningkatkan hambatan
terhadap pertumbuhan. Perbaikan pertumbuhan tersebut didukung peningkatan
kadar klorofil a dan b, laju fotosintesis, aktivitas CAT dan APX disertai penurunan
kadar MDA.
Percobaan 2 dilaksanakan di PT Waru Kaltim Plantation (PT WKP)
Kalimantan Timur pada lahan dengan kejenuhan Al > 75% dari tahun 2018 sampai
2019. Percobaan ini terdiri dari dua sub Percobaan yaitu (1) pengaruh senyawa
eksogen tunggal terhadap induksi toleransi cekaman Al dan (2) pengaruh kombinasi
berbagai senyawa eksogen terhadap induksi toleransi cekaman Al. Sub-percobaanii
2.1 menggunakan RAK split-split plot dengan 3 ulangan, yaitu teknik aplikasi
(penyiraman piringan/PP dan penyemprotan daun/PD) sebagai petak utama, jenis
senyawa eksogen (kalsium, asam sitrat dan ethepon) sebagai anak petak dan
konsentrasi (0, 25, 50 dan 100 ppm) sebagai anak anak petak. Tanaman kontrol
menunjukkan jumlah tandan afkir dan kadar MDA tinggi disertai laju fotosintesis,
aktivitas enzim CAT dan APX yang rendah. Aplikasi kalsium dan asam sitrat
mampu meningkatkan bobot tandan rata-rata (BTR), laju fotosintesis, aktivitas
CAT dan APX disertai penurunan kadar MDA dan jumlah tandan afkir. Respon
tersebut diduga dipengaruhi perbaikan sifat kimia tanah; dalam perlakuan kalsium
dan asam sitrat secara PP menurunkan Al-dd disertai peningkatkan pH,
ketersediaan fosfat, Ca-dd, K-dd, Mg-dd, dan kejenuhan basa. Peningkatan
produksi pada perlakuan kalsium 100 ppm secara PP mencapai 98,5% untuk BTR
dan 80,8% untuk produktivitas terhadap potensinya.
Sub Percobaan 2.2 pengaruh kombinasi berbagai senyawa eksogen dilakukan
di lokasi yang berdekatan dengan sub Percobaan 2.1 sebagai upaya peningkatan
keefektifan senyawa eksogen. Perlakuanya terdiri dari: 1) kontrol, 2) kalsium, 3)
kalsium + asam salisilat, 4) kalsium + asam salisilat + asam sitrat, 5) kalsium +
asam salisilat + asam sitrat + boron, dan 6) kalsium + asam salisilat + asam sitrat +
boron + cuprum masing-masing 50 ppm dengan teknik aplikasi PP dan PD
menggunakan RAK split plot. Kombinasi no 3, 4, 5 dan 6 tidak berpengaruh
terhadap hara daun sedangkan kimia tanah berbeda nyata seperti peningkatan pH,
fosfat tersedia, Ca-dd, K-dd, kejenuhan basa dan Al-dd menurun. Respon fisiologi
tanaman terlihat pada peningkatan laju fotosintesis disertai peningkatan aktivitas
CAT dan APX dengan kadar MDA menurun pada 3 hari setelah perlakuan (HSP)
dan 7 HSP. Seiring peningkatan laju fotosintesis, jumlah tandan afkir menurun dan
BTR meningkat dengan jumlah tandan normal meningkat. Kombinasi no 3 secara
PP menunjukkan peningkatan BTR dan produktivitas tertinggi mencapai 97,1% dan
83,9% terhadap potensinya. Teknik aplikasi secara PP menunjukkan hasil lebih
baik dibandingkan teknik PD. Semua perlakuan tidak berpengaruh nyata terhadap
total bunga dan total tandan.
Percobaan 3 aplikasi berbagai senyawa eksogen pada bunga dan buah
dilakukan untuk meningkatkan produksi dan rendemen minyak. Percobaan
dilakukan September 2018 sampai Mei 2019 di PT WKP, Kalimantan Timur pada
tanaman umur 4 tahun. Kombinasi senyawa yang diujikan ialah 1-
metylcyclopropene (1-MCP) (0, 100, 200 dan 300) ppm, kalsium (0 dan 50 ppm)
dan naphthalene acetic acid (NAA) (0 dan 200 ppm) menggunakan RAK. Aplikasi
kalsium dan NAA dilakukan pada bunga pasca anthesis, sedangkan 1-MCP ketika
fase buah mulai memerah hingga panen setiap 10 hari. Semua perlakuan mampu
meningkatkan panjang buah, bobot buah, nisbah bobot buah per tandan, nisbah
bobot basah dan bobot kering mesokarp per buah, nisbah minyak per bobot basah
dan bobot kering mesocarp, walaupun pengaruh terhadap fruit set dan nisbah
minyak per tandan terlihat kecil. Aplikasi 100 ppm 1-MCP + 50 ppm kalsium + 200
ppm NAA memperoleh nisbah minyak per bobot kering mesocarp tertinggi sebesar
82,0%. Aplikasi eksogen ini dapat diterapkan pada tandan kelapa sawit sebagai
upaya meningkatkan rendemen. | id |
| dc.description.abstract | Oil palm is one of the important commodities in the Indonesian economy
from the non-oil and gas sector, but is predominantly cultivated on acidic mineral
soils where aluminum (Al) stress is one of the main limiting factors. Al stress
inhibits plant growth and development so that production is below its potential and
improvement efforts are required. Exogenous compounds could reduce to Al
toxicity such as calcium, citric acid, salicylic acid, hormones and osmoprotectants.
This research aims to obtain feed techniques to increase the productivity and oil
yield of oil palm through the addition of PGRs, calcium, microelements B, and Cu
in acidic soils with high Al. This study consisted of three trials where conducted in
the plantation area of PT Astra Agro Lestari, Tbk.
The Experiment 1 was carried out from September 2018 to April 2019 in a
greenhouse at PT Gunung Sejahtera Ibu Pertiwi, Central Kalimantan. Oil palm
seedlings aged 10 weeks after planting transferred to the hydroponic system in
nutrient culture. The Experiment 1 consisted of two sub-Experiments, namely
experiment of Al toxicity and effect of various exogenous compounds on the
tolerance induction to Al stress. The variables measured were the malondialdehyde
(MDA) levels, the catalase (CAT) and ascorbate peroxidase (APX) activity,
photosynthesis rate, and vegetative growth. Sub-experiment 1.1 used various Al
concentrations such as 0, 100, 200, 400, 800, and 1600 μM. The addition of 400
μM Al or more decreased root length, root and shoot dry weight, photosynthetic
rate, CAT, and APX activity accompanied by increased MDA levels. The growth
inhibition at 400 μM Al showed at root length 33,9%, root dry weight 32,75%, and
shoot dry weight 46,78%. Based on these results, a concentration of 400 µM Al
could be used in the selection of Al tolerant oil palm varieties.
Sub-experiment 1.2 the effect of various exogenous compounds on the
tolerance induction to Al stress used various concentrations of calcium, citric acid,
ethephon and peat water in nutrient culture containing 400 µM Al. The
concentrations of calcium, citric acid, and ethylene added were 0, 25, 50, and 100
ppm, while peat water was 0, 100, 200, and 300 ppm. The addition of calcium, citric
acid, and peat water could improve the growth of plants on Al stress, while the
addition of ethylene increased hamper to growths. The improvement in these
growths supported by increased levels of chlorophyll a and b, the rate of
photosynthesis, CAT and APX activity accompanied by a decrease in MDA levels.
Experiment 2 was carried out at PT Waru Kaltim Plantation (PT WKP) East
Kalimantan on upland with Al saturation > 75% from 2018 to 2019. The
Experiment 2 consisted of two sub-Experiments, namely (1) the effect of a single
exogenous compound on the induction of tolerance to Al stress and (2) the effect of
the combination of various exogenous compounds on the induction of tolerance to
Al stress. The sub-Experiment 2.1 conducted an RCBD split-split plot design with
3 replications, namely application techniques (watering circle/WC and foliar sprayiv
/FS) as the main plot, kinds of exogenous compounds (calcium, ethylene, citric
acid) as subplots and their concentrations (0, 25, 50, 100 ppm) as sub-sub plot.
Untreated plants showed a large number of rejected bunches with MDA level of
highly accompanied by a low of the rate of photosynthesis, CAT and APX enzyme
activity. Application of calcium and citric acid could increase the average bunch
weight (ABW), the rate of photosynthesis, CAT and APX activity accompanied by
a decrease in MDA levels and the number of rejected bunches. These responses
thought to be influenced by changes in soil chemistry, where the treatment of
calcium and citric acid by WC decreased Al exchangeable and increased soil pH,
availability of phosphorus, Ca-exchangeable, K-exchangeable, Mg-exchangeable,
and base saturation. The increase of production in the 100 ppm calcium treatment
by WC reached 98,5% for ABW and 80,8% for productivity towards its potential.
Sub-Experiment 2.2 the effect of the combination of various exogenous
compounds was carried out in a location close to sub-Experiment 2.1 as an effort to
increase the effectiveness of exogenous compounds. The treatments consisted of 1)
untreated, 2) calcium, 3) calcium + salicylic acid, 4) calcium + salicylic acid + citric
acid, 5) calcium + salicylic acid + citric acid + boron, and 6) calcium + salicylic
acid + citric acid + boron + copper respectively 50 ppm with WC and FS application
techniques used an RCBD split-plot design. Combinations 3, 4, 5 and 6 had no
effect on leaf nutrients while soil chemistry was significantly different, such as
increasing pH, available phosphate, Ca-exchangeable, Mg-exchangeable, Kexchangeable, base saturation and Al-exchangeable decreased. The plant
physiological response was seen in an increase in the rate of photosynthesis
accompanied by an increase in CAT and APX activity with decreased MDA levels
at 3 days after treatment (DAT) and 7 DAT. As the rate of photosynthesis increases,
the number of rejected bunches decreases and ABW increases. The combination
treatment 3 by WC showed the highest increase in ABW and productivity reached
97,1% and 83,9% of its potential. The watering circle application technique shows
better results than the foliar spray technique. All treatments were no significant
effect on total flowers and bunches.
Experiment 3 application of various exogenous compounds to flowers and
fruit was carried out to increase oil production and yield. Experiments were
conducted from September 2018 to May 2019 at PT WKP, East Kalimantan on 4
years old plants. The compounds combination tested were 1-metylcyclopropene (1-
MCP) (0, 100, 200 and 300) ppm, calcium (0 and 50 ppm), and naphthalene acetic
acid (NAA) (0 and 200 ppm) used RCWC design. Calcium and NAA were applied
to flowers after anthesis, while 1-MCP applied to the fruit phase reddened until
harvest per 10 days. All treatments could raise fruit length, fruit weight, fruit to
bunch, the ratio of wet and dry mesocarp per fruit and oil to wet and dry mesocarp,
although the impact on fruit set and oil to bunch was small. Application of 100 ppm
1-MCP + 50 ppm calcium + 200 ppm NAA afforded the highest the ratio of oil per
dry mesocarp by 82,0%. The exogenous compound could apply to oil palm bunches
as an effort to increase oil yield. | id |
