Response of finger millet (Eleusine coracana(L.) Gaertn) to live mulch and stale seedbed

Abstract

The research work titled “Response of finger millet (Eleusine coracana (L.) Gaertn) to live mulch and stale seedbed was conducted at College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, during 2021-2023. The primary aim of the study was to assess the effect of live mulch and stale seedbed on weed control, growth and yield of finger millet. The field experiment was conducted in the model organic farm at College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during summer 2022-23 (February 2023-May 2023). The experiment was laid out in randomized block design with two factors in three replications. The first factor was land preparation (L), viz., normal seedbed (l1), stale seedbed with light raking (l2) and stale seedbed with flaming (l3) and the second factor was live mulches (M) viz., no mulch (m1), cowpea (m2), green gram (m3) and cluster bean (m4). The variety used in the study was PPR 2700 (Vakula). The live mulches were sown in 1:1 proportion and left in the interrow spaces as organic mulch by wheel hoe weeding at 50 per cent flowering stage (40 DAS of the mulch crop). The crop was raised as per Ad hoc POP recommendations (organic) of Kerala Agricultural University (KAU, 2017) Stale seedbed with light raking (l2) resulted in taller plants of finger millet at 20 DAS, 40 DAS and harvest. It also produced higher tiller count at 20 DAS and 60 DAS and higher DMP per plant at 20 DAS, 60 DAS and harvest. In finger millet, cowpea live mulch (m2) recorded taller plants and DMP per plant at all stages of observation. Tiller count was significant only at 20 DAS and 60 DAS and live mulching with cowpea resulted in higher tiller count at both stages The interaction effect of land preparation and live mulches revealed that, in finger millet the treatment l2m2 resulted in taller plants, higher tillers m-2 and DMP per plant at 60 DAS and harvest. Stale seedbed with flaming (l3) resulted in higher CGR and RGR at 20 DAS-40 DAS in finger millet, however, at both 40 DAS-60 DAS and 60 DAS-harvest, the highest CGR and RGR were observed in l2. Cowpea live mulch resulted in significantly higher CGR and RGR at 20 DAS- 40 DAS and LAI at 20 DAS and 40 DAS in finger millet.213 The CGR and RGR of finger millet at 20 DAS-40 DAS were also higher in l2m2. However, l2m1 showed higher CGR and RGR at 40 DAS-60 DAS and l2m4 showed higher CGR at 60 DAS- harvest. Stale seedbed with light raking resulted in higher number of fingers per ear head (12.87) and ear head weight (15.78 g) and it was comparable with l3. The treatment l2 also resulted in the highest number of productive tillers m-2 (45.3), 1000 grain weight (1.50 g), grain yield (661 kg ha-1) and harvest index (0.310). The percentage increase in grain yield in l2 compared to l1 was 17.25. The lowest weed index (20.47 %) was also observed in l2. The yield attributes of finger millet, productive tiller count (50.2 no. m-2), ear head weight (18. 62 g) and 1000 grain weight were also higher in cowpea live mulch. The grain yield of finger millet was also the highest in cowpea live mulch (717 kg ha-1). Compared to control (without mulch), the percentage yield increase due to live mulching with cowpea was 49.06. Cowpea live mulch also resulted in higher harvest index (0.321) and the lowest weed index. The treatment l2m2 resulted in higher number of productive tillers m-2 (53.3 no. m-2), ear head weight and 1000 grain weight in finger millet. It also produced significantly higher grain yield (832 kg ha-1) and harvest index (0.341) and the lowest weed index (0.00). Compared to l1m1, the yield increase observed in l2m2 was 131.8 per cent. The crude protein content and starch content of finger millet grain was the highest in l2. The quality parameters, viz., crude protein content and starch content of finger millet grain were also higher in cowpea live mulch. The treatment l3m2 resulted in higher crude protein content of finger millet grain (14.27%) and higher starch content in l2m2 (82.19%). The N and P uptake by finger millet at harvest were found to be higher in l2 and K uptake in l3. Cowpea live mulch had the highest N and K uptake by finger millet. It also recorded higher P uptake but comparable with m3 and m4. The treatment l2m2 had the highest N and K uptake by finger millet at harvest stage. It also recorded higher P uptake but comparable with l3m3.214 Stale seedbed with light raking resulted in lower N and P uptake by weeds and SSB with flaming had lower K uptake by weeds at 60 DAS. Cowpea had the lowest N uptake by weeds at 60 DAS, however, lower P and K uptake by weeds were observed in green gram. Among the treatments at 60 DAS, l3m2 resulted in lower N uptake by weeds, however, l2m3 had lower P uptake and l3m1 had lower K uptake by weeds. Land preparation did not significantly influence the dehydrogenase enzyme activity at 60 DAS. However, treatment l3 resulted in the highest urease enzyme activity in soil. Land preparation did not have any significant effect on SOC and available N content in the soil at the post-harvest stage. However, l2 had the highest available P in the soil and available K in l3. Green gram resulted in the highest dehydrogenase enzyme activity in soil at 60 DAS. However, urease enzyme activity was the highest in cowpea (m2). At post-harvest stage, m2 had the highest available N and K in the soil, however, higher available P in m3. The treatment l2m2 resulted in higher dehydrogenase and urease enzymes activity in soil at 60 DAS. The treatment l1m2 resulted in significantly higher available N and SOC in the soil at post-harvest stage. The available P in the soil was the highest in l2m3. The treatment l2m2 had higher available K in the soil but comparable with l3m4. SSB with flaming had the lowest total weed density, however, l2 had the lowest total weed dry weight and the highest WCE. Among the live mulches, cowpea live mulch had the lowest total density of weeds, weed dry weight and the highest WCE at 60 DAS. The treatment l2m2 had lower total weed density at 60 DAS. However, the lowest dry weight of weeds was observed in l2m2 and l2m3. The highest WCE was observed in l2m3. Land preparation had remarkable effect on N, P and K content of live mulches at 50 per cent flowering stage. Normal seedbed (l1) resulted in higher N content of live mulches, P content in l2 and K content in l3. Significant variations were observed in the N, P and K content of live mulches at 50 per cent flowering stage. The treatment m2 showed higher N content, however, m3 showed higher P and K content. Plant height and branches per plant did not show215 variation among the mulches. The DMP showed significant variations among the live mulches and the highest DMP was observed in m2. Amongst the treatments, l1m2 recorded higher N content of live mulches, P content in l1m4 and K content in l3m3. Live mulches showed significant variations in plant height and number of branches among different land preparation methods. In cowpea, taller plants and higher branches per plant were observed in NSB, in green gram, taller plants and branches per plant were observed in SSB with flaming and in cluster bean, SSB with light raking resulted in taller plants and higher branches per plant. Among the treatments, the highest gross return (₹ 83200 ha-1), net return (₹ 29458 ha-1) and BCR (1.55) were observed in l2m2. From the results, it could be concluded that stale seedbed with light raking followed by live mulching with cowpea in 1:1 proportion (l2m2) and its incorporation at 50 per cent flowering stage using wheel hoe weeder could be recommended as a cost- effective weed management practice for better weed control, higher yield, net return and B:C ratio in finger millet. The yield increase observed in l2m2 over non stale seedbed without live mulch (l1m1) (control) was 131.8 per cent and increase in net return over l1m1 was ₹ 31800 ha-1.