Effect of sowing seasons and harvests stage on morphological characteristics, yield potential, nutritive value, and digestibility of Rhodes grass (Chloris gayana L.)

Abstract

Rhodes grass (Chloris gayana L.) is a multi-cut, C4 specie and widely cultivated grass under tropical and subtropical climatic conditions, famous for its ability to tolerate harsh dry summer condition, soil salinity, and light frost of winter season. The study was aimed to investigate the effect of different sowing season and harvest on biomass yield, nutrient composition, digestibility (in vitro) and morphological characteristics of C. gayana The seeds were in 20 plots (5 m × 15 m) under randomize complete block design (RCBD) and seed rate of 8 kg/ha during each sowing season. The sowing was undertaken through broadcasting method in four different seasons/year (winter, spring, summer, autumn). The samples were collected at the three successive harvest/cuts (1st cut 70 days after sowing (DAS), 2nd cut after 40 days, and third cut at 40 days after the second cut) for fresh matter (FM) and dry matter (DM) yields and samples were studied using PROC MIXED procedure. Higher variation was observed (P < 0.05) for germination rate (%), tillers/ plant (no.) and maximum height of plant (cm) during spring season. The significant variation for FM (18.85 vs 11.83 tons ha-1), DM (5.20 vs 3.35 tons ha-1), and in vitro digestibility (61.0 vs 54.4 g/100 g) were observed during spring season compared to rest of the seasons. The harvest numbers also displayed significant variation for FM, DM yield, nutrient composition, and in vitro digestibility of Rhodes grass. Advancing from first harvest towards the third harvest there was an increase in the yield (tons ha-1) of FM (11.54 vs 17.56), DM (3.01 to 4.94). The highest value for crude protein (CP) (0.51 vs 0.25 tons ha-1) and nutrient detergent fibre (3.32 vs 2.10 tons ha-1) were observed during the third harvest and the lowest value were recorded during the first harvest. The current study displayed that Rhodes grass should be sown during spring season for maximum yield including biomass yield, nutritive value, and in vitro digestibility. Moreover, advance harvests i.e., second, third etc., may improve biomass yield, and fibre digestibility of the Rhodes grass.