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2016 - 20172
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Author: Amandeep Singh × End date: 2017 ×
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    Refinement of leaf colour chart based fertilizer nitrogen management technology using PAU-LCC in transplanted rice
    (Punjab Agricultural University, Ludhiana, 2017) Amandeep Singh; Varinderpal Singh
    Large field to field variability in inherent soil nitrogen (N) supply restricts efficient fertilizer N use when soil test based fertilizer N recommendations are used in transplanted rice. A field experiment was conducted at PAU, Ludhiana to study spectral properties of transplanted rice to guide need-based fertilizer N application and to study need of basal N application in new rice varieties i.e. PR 121, PR 122, PR123 and PR 124. The spectral properties of rice leaves at different growth stages measured using PAU-LCC (PAU-Leaf colour chart), SPAD (chlorophyll) meter and GreenSeeker optical sensor correlated well with leaf N concentration except at 10 days after transplanting (DAT). The PAU-LCC and SPAD meter readings were poorly correlated with leaf dry weight at early growth stages but correlation improved as growth progressed. The NDVI values integrate intensity of leaf colour greenness and biomass and are thus well correlated with leaf dry weight at different growth stages. Close linear relationship (R2=0.732, n= 504) between PAU-LCC score and SPAD meter readings suggested that PAU-LCC can be used as economical substitute to SPAD for making need based fertilizer N topdressings in transplanted rice. The PAU-LCC 4 guided N applications produced grain yield equivalent to soil test based N applications with saving of 60 kg N ha-1, and thus led to maximum agronomic (46.7 kg kg-1 N) and recovery efficiency (82.5 per cent) of applied fertilizer N. Whereas, PAU-LCC 4.5 guided N management improved grain yield production by 8.47 percent with the use of fertilizer N equivalent to soil test based N management in new rice varieties (PR 121, PR 122, PR123 and PR 124). The basal N dose can be delayed till 10 DAT while using threshold leaf greenness of PAU-LCC 4.5.
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    Effect of biofertilizers on growth and buddability of rough lemon seedlings in containerised nursery system
    (Punjab Agricultural University, Ludhiana, 2016) Amandeep Singh; Thakur, Anirudh
    The present investigations entitled “Effect of biofertilizers on growth and buddability of rough lemon seedlings in containerized nursery system” were carried out during 2014-2015 in Citrus Nursery, Department of Fruit Science, Punjab Agricultural University, Ludhiana. Two commercial growing media (Soil + FYM and Soil + FYM + Cocopeat) used in citrus nursery were fortified with biofertilizers (Azospirillum, phosphate solubilizing bacteria and AM fungi) alone or in combinations. The effect of growing media and biofertilizer combinations was studied on growth of rough lemon and subsequently produced Kinnow plants. In general, the growing media, Soil + FYM + Cocopeat resulted in better growth of rough lemon seedlings and Kinnow mandarin plants as compared to Soil + FYM. Fortification of growing medium with biofertilizers significantly improved growth parameters of rough lemon and Kinnow mandarin plants. In rough lemon seedlings, the highest seed germination, seedling height, seedling girth, number of leaves, leaf area and root growth was recorded with Azospirillum + AM fungi. The highest improvement in growth of Kinnow plants in terms of sprout length, sprout grith, number of leaves and leaf area was also recorded in growing medium Soil + FYM + Cocopeat fortified with Azospirillum + AM fungi. Higher leaf N, P and K content was recorded in growing media soil + FYM + cocopeat, irrespective of the biofertilizer treatments. The colony count of actenomycetes, bacteria and fungi significantly increased by the application of biofertilizers and the effect was more pronounced in the growing media ‘Soil + FYM + Cocopeat’ as compared to ‘Soil + FYM’. The root colonization, spore count of AM fungi, root phosphorous content and phosphorus content in growing media were highest for the biofertilizer combination Azospirillum + AM fungi in the growing media Soil + FYM + Cocopeat. The growing medium Soil + FYM + Cocopeat fortified with Azospirillum + AM fungi resulted in better growth and development of rough seedlings and Kinnow plants.