Analisis Keterkaitan Teknik Budi Daya Petani dan Kesuburan Tanah terhadap Penyakit Tular Tanah pada Tanaman Lada di Bangka

Abstract

Penyakit tular tanah menjadi faktor pembatas penting keberlanjutan produksi lada baik secara kuantitas maupun kualitas di Pulau Bangka. Penyakit tular tanah yang dilaporkan menyerang tanaman lada di Bangka antara lain penyakit kuning, penyakit busuk pangkal batang (BPB), dan jamur akar putih (JAP). Epidemi penyakit tular tanah ditentukan oleh interaksi komponen pembentuk yaitu patogen, inang, dan lingkungan. Manusia sebagai faktor keempat melalui praktik budi dayanya seperti pemilihan varietas, penambahan bahan organik, solarisasi, aplikasi agens hayati dapat memengaruhi ketiga komponen pembentuk tersebut baik secara langsung maupun tidak langsung. Kesuburan tanah sebagai bagian dari faktor lingkungan yang mencakup karakteristik fisik, kimia, dan biologi tanah juga berkontribusi membentuk lingkungan bagi perkembangan patogen dan kesehatan tanaman. Kondisi fisik tanah, pemupukan mineral, defisiensi hara, dan stres lingkungan dilaporkan menjadi faktor predisposisi penyakit tular tanah. Pengendalian penyakit tular tanah lada masih menjadi tantangan yang perlu dijawab. Strategi pengendalian perlu didasari pada pemahaman yang baik mengenai komponen pembentuk penyakit di antaranya komponen manusia yang terkait dengan praktik budi daya oleh petani dan kesuburan tanah sebagai bagian dari komponen lingkungan. Penelitian ini bertujuan mengidentifikasi pengaruh faktor teknik budi daya dan kesuburan tanah yang berperan dalam perkembangan penyakit tular tanah pada tanaman lada di Bangka. Penelitian dilakukan di Kabupaten Bangka Barat, Bangka, Bangka Tengah, dan Bangka Selatan Provinsi Kepulauan Bangka Belitung. Metode penelitian meliputi pengamatan insidensi penyakit, wawancara terstruktur kepada petani, pengambilan sampel tanah dan jaringan tanaman, dan analisis kimia dan fisik tanah dan jaringan tanaman. Pengaruh teknik budi daya terhadap insidensi penyakit dianalisis dengan chi-square pada a= 0,05. Hubungan antara kesuburan tanah dan penyakit dianalisis menggunakan analisis regresi subset terbaik dan dilanjutkan dengan analisis fit regresi untuk membuat model terbaik. Hubungan antar penyakit tular tanah dianalisis dengan fit regresi. Data hara jaringan tanaman dianalisis secara kualitatif deskriptif. Hasil penelitian menunjukkan faktor budi daya yang berpengaruh terhadap insidensi penyakit kuning adalah umur tanaman, populasi tanaman, asal bibit, pola tanam, pemberian bahan organik, dan kondisi naungan. Insidensi penyakit kuning lebih tinggi pada tanaman berumur =3 tahun dibandingkan tanaman berumur >3 tahun. Kerapatan populasi >600 tanaman per lahan memicu insidensi penyakit kuning. Penggunaan bibit lada yang berasal dari pertanaman sebelumnya memicu insidensi penyakit kuning dan BPB yang lebih tinggi dibandingkan mendatangkan bibit dari luar. Pola tanam lada tumpang sari kelapa sawit menunjukkan insidensi penyakit kuning lebih tinggi dibandingkan tumpang sari bukan kelapa sawit. Penambahan bahan organik pada pertanaman lada dapat menekan insidensi penyakit kuning. Tanaman dengan naungan menunjukkan nilai insidensi penyakit kuning dan BPB yang lebih rendah. Serangan BPB dipicu oleh lahan yang tidak tersanitasi sehingga menimbulkan sumber inokulum. Insidensi JAP dipengaruhi kegiatan pemangakasan sulur, dimana pertanaman yang dipangkas menunjukkan insidensi JAP yang lebih tinggi. Secara umum teknik budi daya tidak secara langsung memengaruhi perkembangan patogen, melainkan memengaruhi kebugaran tanaman dan agroekosistem yang kemudian berkontribusi pada pembentukan epidemi penyakit. Model regresi terbaik menunjukkan C-organik berkorelasi negatif terhadap insidensi penyakit kuning, yang berarti pertambahan nilai C-organik tanah akan menekan penyakit kuning. Insidensi BPB, kemasaman dapat ditukar Al3+, dan Seng (Zn) berkorelasi positif terhadap insidensi penyakit kuning. Peningkatan ketiga faktor tersebut akan memicu insidensi penyakit kuning lebih tinggi. Model pengaruh kesuburan tanah terhadap insidensi BPB menunjukkan Besi (Fe) berkorelasi positif terhadap perkembangan BPB. Akumulasi besi dalam tanah secara langsung mendorong pertumbuhan cepat patogen. Sedangkan K2O potensial berkorelasi negatif terhadap BPB. Model terbaik perkembangan insidensi JAP dipengengaruhi oleh nilai pH tanah dan P2O5 tersedia. Peningkatan nilai kedua faktor tersebut akan menekan insidensi JAP. Analisis hara jaringan daun antara tanaman sehat dan sakit kuning menunjukkan adanya perbedaan status. Tanaman terserang penyakit kuning erat hubungannya dengan defisiensi Kalsium (Ca) dan Magnesium (Mg), serta ketidakseimbangan Nitrogen (N) pada tanaman. Penyakit tular tanah tanaman lada di Pulau Bangka saling berinteraksi satu dengan lainnya. Model regresi menunjukkan insidensi penyakit kuning secara nyata berkorelasi positif dengan BPB, dan memiliki hubungan antagonis dengan keberadaan JAP.

Soil-borne diseases are an important limiting factor for the sustainability of black pepper production both in quantity and quality on Bangka Island. Soil-borne diseases reported to attack black pepper in Bangka include yellow disease, foot rot, and white rot. The epidemic of soil-borne diseases is determined by the interaction of the forming components, namely the pathogen, host, and environment. Humans as the fourth factor through their cultivation practices such as cultivar selection, organic matter addition, solarization, application of biological agents can affect the three constituent components either directly or indirectly. Soil fertility as part of the environmental factors that include physical, chemical, and biological characteristics of soil also contributes to shape the environment for pathogen development and plant health. Soil physical conditions, mineral fertilization, nutrient deficiencies, and environmental stress are reported to be predisposing factors for soil-borne diseases. Control of soil-borne diseases of black pepper remains a challenge that needs to be addressed. Control strategies need to be based on a good understanding of the components that form the disease, including the human component related to cultivation practices by farmers and soil fertility as part of the environmental component. This study aimed identify the effect of cultivation techniques and soil fertility factors that play a role in the development of soil-borne diseases in black pepper in Bangka. The research was conducted in West Bangka, Bangka, Central Bangka, and South Bangka districts of Bangka Belitung Islands Province. Research methods included observation of disease incidence, structured interviews with farmers, soil and plant tissue sampling, and chemical and physical analysis of soil and plant tissue. The effect of cultivation techniques on disease incidence was analyzed by chi-square at a= 0.05. The relationship between soil fertility and disease was analyzed using best subset regression analysis and followed by fit regression analysis to create the best model. Correlations between soil-borne diseases were analyzed by fit regression. Plant tissue nutrient data were analyzed qualitatively descriptively. The research results showed that cultivation factors that affected the incidence of yellow disease were plant age, plant population, seedling source, planting pattern, organic matter addition, and shading. Yellows disease incidence was higher in plants =3 years of age than in plants >3 years of age. Population densities of >600 plants per field triggered yellow disease incidence. The use of black pepper seedlings from previous crops triggered a higher incidence of yellow disease and foot rot than using seedlings from outside. The intercropping pattern of black pepper with palm oil showed a higher incidence of yellow disease than intercropping with non-palm oil. The addition of organic matter to pepper crops reduced the incidence of yellow disease. Shaded plants showed lower value of yellow disease and foot rot incidence. Foot rot was triggered by unsanitized fields that provided a source of inoculum. White rot incidence was influenced by vine pruning, where pruned plants showed higher incidence of white rot. In general, cultivation techniques did not directly impact pathogen development, but rather affected plant health and agroecosystem which then contributed to the establishment of disease epidemics. The best regression model showed that C-organic was negatively correlated with yellow disease incidence, meaning that an increase in soil C-organic value would reduce yellow disease. Foot rot incidence, exchangeable acidity Al3+, and Zinc (Zn) were positively correlated to yellow disease incidence. An increase in these three factors caused higher yellow disease incidence. The model of the effect of soil fertility on fot rot incidence showed that Iron (Fe) is positively correlated to pathogen development. The accumulation of Iron in the soil directly stimulated the rapid growth of foot rot. While K2O was potentially negatively correlated to foot rot. The best model of white rot incidence development was influenced by soil pH and available P2O5. Increasing the values of these two factors will reduce white rot incidence. Nutrient analysis of leaf tissue between normal and yellow-diseased plants showed a difference in their status. Yellow disease was closely related to Calcium (Ca) and Magnesium (Mg) deficiency, as well as Nitrogen (N) imbalance in plants. Soil-borne diseases of black pepper in Bangka Island interact with each other. Regression models showed that yellow disease incidence was significantly positively correlated with foot rot, and had an antagonistic relationship with white rot.