Performance of semi dry rice in response to nutripriming and sowing methods in onattukkara sandy plains

Abstract

The study entitled “Performance of semi-dry rice in response to nutripriming and sowing methods in Onattukara Sandy Plains” was conducted during the period 2022-2024. The objective was assessment of the influence of nutriprimed seeds sown with seed drill on the growth and yield of semi-dry rice in Onattukara Sandy Plains. The research work comprised a pot culture experiment conducted at Department of Agronomy, College of Agriculture, Vellayani and a field experiment carried out in farmer’s field at Onattukara Sandy Plains of Alappuzha district. The short duration rice variety 'Bhagya' was used in the experiments. A pot culture experiment was conducted in completely randomized design to identify three most effective nutripriming treatments for field experimentation. Ten treatments were evaluated in three replications, consisting of seeds nutriprimed with KCl 0.1% (T1), KNO3 0.1% (T2), 19:19:19 0.1% (T3), KCl 0.1% + ZnSO4 0.01% (T4), KNO3 0.1% + ZnSO4 0.01% (T5), 19:19:19 0.1% + ZnSO4 0.01% (T6), KCl 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% (T7), KNO3 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% (T8), 19:19:19 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% (T9), and hydroprimed seeds as control (T10). Nutriprimed seeds exhibited superior germination performance compared to hydroprimed control, as evidenced by higher values for germination percentage, germination index, mean daily germination, speed of germination, mean germination rate, coefficient of rate of germination, germination rate index, shoot and root length, shoot and root dry weight, seedling vigour index I, and seedling vigour index II. Conversely, these nutriprimed seeds demonstrated lower values for time spread of germination, mean germination time, and time to 50 per cent germination. Scores were assigned to each germination parameter, seedling growth and vigour index. The three treatments with the highest overall scores were advanced to field experiment. The best performing nutripriming treatments thus selected were, 19:19:19 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% (NPK+Zn+B), 101

19:19:19 0.1% + ZnSO4 0.01% (NPK+Zn), and KNO3 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% (NK+Zn+B). The field experiment was laid out in randomized block design during virippu season (May 2024 to August 2024), to evaluate the influence of various nutripriming treatments and sowing methods on the growth and yield of semi-dry rice. Eight treatments replicated thrice, included NPK+Zn+B nutriprimed seeds sown traditionally (T1), NPK+Zn+B nutriprimed seeds sown using seed drill (T2), NPK+Zn nutriprimed seeds sown traditionally (T3), NPK+Zn nutriprimed seeds sown using seed drill (T4), NK+Zn+B nutriprimed seeds sown traditionally (T5), NK+Zn+B nutriprimed seeds sown using seed drill (T6), non-nutriprimed seeds sown traditionally as control (T7), and non-nutriprimed seeds sown using seed drill as control (T8). Seeds nutriprimed with NPK+Zn+B and sown using seed drill (T2) resulted in taller plants, greater number of tillers per square metre, higher leaf area index, and increased total chlorophyll content. T2 also had higher dry matter accumulation per hill, resulting in higher crop growth rate (26.01 g m-2 d-1) and relative growth rate (0.034 g g-1 d-1) during 40 to 60 DAS. Moreover, T2 resulted in increased number of productive tillers (444 no. m-2), greater number of spikelets per panicle (127 nos.), filled grains per panicle (110 nos.), and higher grain weight per panicle (3.13 g). Treatment T2 exhibited the lowest sterility percentage (11.3%). These improved growth and yield attributes in T2 resulted in greater grain (4986 kg ha-1) and straw (6215 kg ha-1) yields, and higher harvest index (0.44). Non-nutriprimed seeds sown traditionally (T7) yielded 3114 kg ha-1 grain, while non-nutriprimed seeds sown using seed drill (T8) produced a grain yield of 3578 kg ha-1. This represented a 14.9 per cent increase in grain yield due to the use of seed drill. Seeds nutriprimed with NPK+Zn+B and sown using seed drill (T2) achieved higher grain yield (4986 kg ha-1), accounting for 39.4 per cent increase compared to T8. 102

Seeds nutriprimed with NPK+Zn+B and sown with seed drill (T2) recorded lower absolute density of weeds, resulting in lower weed dry weight. T2 also resulted in higher crop uptake of N (154kg ha-1), P (25 kg ha-1) and K (96 kg ha-1). Post harvest soil analysis revealed decreased available N, P and K (241, 34.44 and 168 kg ha-1, respectively) in T2 compared to pre-treatment levels. Among the treatments, seeds nutriprimed with NPK+Zn+B and sown using seed drill (T2) recorded the highest net income (₹ 64167 ha-1) and benefit cost ratio (1.44). From the study it was concluded that, seeds nutriprimed with 19:19:19 0.1% + ZnSO4 0.01% + Na2B8O13 0.01% and sown using seed drill is an effective method for better crop establishment and higher grain yield in semi-dry rice cultivation in the Onattukara Sandy Plai