MSc

A field experiment on “Zinc and boron nutrition in groundnut (Arachis hypogaea L.) for Onattukara sandy plain” was undertaken during 2017-19 to evaluate the effect of zinc and boron nutrition on growth, yield and quality of groundnut (Arachis hypogaea L.) in the summer rice fallows of Onattukara and to work out the economics of cultivation. The experiment was conducted during December 2018 to April 2019 in farmer’s field at Onattukara region of Alappuzha district.
The experiment was laid out in randomized block design with 12 treatments replicated thrice. The treatments were T1 - soil application of Zn @ 5 kg ha-1 as ZnSO4 ; T2 - soil application of Zn @ 5 kg ha-1 as Zn-EDTA ; T3 - soil application of B @ 1 kg ha-1 as borax ; T4 - soil application of Zn @ 2.5 kg ha-1 as ZnSO4 + B @ 0.5 kg ha-1 as borax ; T5 - foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 days after emergence (DAE), T6 - foliar application of 0.5 per cent borax at 30, 45 and 60 DAE; T7 - foliar application of 0.25 per cent ZnSO4 + 0.25 per cent borax at 30, 45 and 60 DAE; T8 - seed treatment with ZnSO4 (250 mg kg-1); T9 - seed treatment with borax (100 mg kg-1); T10 - seed treatment with ZnSO4 (250 mg kg-1) + borax (100 mg kg-1); T11 - soil test based recommendation and T12 - control. FYM @ 2 t ha-1, N: P2O5: K2O @ 10:75:75 kg ha-1 (as basal) and lime 1.5 t ha-1 (at flowering) were applied uniformly to all treatments. The bunch type groundnut variety, CO 7 was sown at a spacing of 15 cm x 15 cm.
The growth attributes of groundnut were recorded at 30, 45, 60 DAE and at harvest. Among the treatments, foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5), soil application of ZnSO4 @ 5 kg ha-1 (T1) and soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4) recorded significantly higher growth parameters viz., plant height, number of branches, leaf area and number of nodules per plant. At all stages of growth, soil application treatments recorded more number of nodules. The physiological parameters such as CGR, NAR, LAI, and LAD recorded during 15 to 30 and 30 to 45 DAS, also varied with Zn and B nutrition. Higher CGR values were obtained with soil application of ZnSO4 @ 5 kg ha-1 (T1) and was on par with foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5). During 30 to 45 DAS, NAR was found to be significant and recorded higher values in all treatments except seed treatment. Leaf area index, LAI and LAD were higher with soil application of ZnSO4 @ 5 kg ha-1 (T1) and was comparable with ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4) during 15 to 30 DAS and 30 to 45 DAS.
The results revealed that yield parameters viz., number of pods per plant, 100 kernel weight and shelling percentage varied significantly with the treatments. Number of pods per plant was higher with foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5) and was on par with T11, T4, T7 and T1. Shelling percentage (70.75 %) was higher with soil application of ZnSO4 @ 5 kg ha-1 (T1) and was on par with foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5).
Kernel yield was significantly higher (1523 kg ha-1) with foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5) and was on par with soil application of ZnSO4 @ 5 kg ha-1 (T1) and soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4). Haulm yield (3978 kg ha-1) was higher with soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4) and was comparable with all treatments except T9 and T10.
Protein content of seed (23.2 %) was higher with soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4) and was on par with all treatments except T2, T9 and T12. Oil content (49.38 %) and oil yield (752.2 kg ha-1) were higher with foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5) and was comparable with soil application of ZnSO4 @ 5 kg ha-1 (T1) and soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4).
Higher uptake of N, S and Zn were observed with T1, T4 and T5. The results on soil nutrient status after the experiment indicated that there was a build up of available N, K, B and Zn status after the experiment and the soil nutrient status of zinc and boron were higher with soil application treatments.
The results revealed that soil application of ZnSO4 @ 5 kg ha-1 (T1), soil application of ZnSO4 @ 2.5 kg ha-1 + borax @ 0.5 kg ha-1 (T4) and foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 DAE (T5) recorded higher net income and benefit - cost ratio.
From the present study, it can be concluded that soil application of Zn @ 5 kg ha-1 as ZnSO4 or soil application of Zn @ 2.5 kg ha-1 as ZnSO4 + B @ 0.5 kg ha-1 as borax or foliar application of 0.5 per cent ZnSO4 at 30, 45 and 60 days after emergence along with the recommended dose of FYM @ 2 t ha-1, N: P2O5: K2O @ 10:75:75 kg ha-1 (as basal) and lime 1.5 t ha-1 (at flowering) can be recommended for better growth, yield, quality and profitability of groundnut in the Onattukara sandy plain.