Ginger Production in India and Other South Asian Countries: Mulching

Mulching of beds with green leaves is an important and essential operation in ginger cultivation. The effect of mulching on growth and yield of ginger has already been established from various studies. Mulching is essential for weed control, for moisture conservation and to protect the beds from the beating action of rain. Heavy mulch can change the physical and chemical environment of the soil underneath, resulting in the increased availability of P and K. Mulching increased the germination and growth of plants in terms of height and number of tillers. Weed growth in the control plots was much higher than the plots mulched.

Applications of leaf mulch immediately after planting and 6 weeks after using a total of 20 t/ha of green leaves resulted in 200 percent increase in yield over the nonmulched crop, and this was found sufficient in the ginger-growing areas of the higher elevations of Western Ghats, South India. In the plains, mulching the crop with 30 t/ha of green leaves has been recommended. Immediately after planting, the beds should be mulched with 15 t/ha of green leaves, which is repeated with 7.5 t/ha each at 2 and 4 months after planting. Mulching is done coinciding with weeding, top dressing, and earthing up. Among the different mulch materials, leaves of Glycosmis pentaphylla, Glyricidia maculata, and Artocarpus altilis were found to produce good results.

In trials with the ginger cv. Maran, Mohanthy (1977), at Pottangi (Orissa), India, reported that when the plants were mulched with (1) banana leaves, (2) grass, or (3) soil, the best results with regard to sprouting, yield, suppression of weeds, and prevention of soil erosion were obtained in mulching with banana leaves. Mishra and Mishra (1982) reported that mulching with dry leaves markedly suppressed the early weed growth and increased the crop emergence, growth, and yield. They also reported that application of weedicides, 2, 4, dichlorophenoxy acetic acid (2,4-D), or Atrazine together with mulching gave the highest yield and returns in ginger.

In Assam, India, the highest yield of fresh ginger (24 t/ha) was recorded with green leaf mulch. Mohanty et al. (1990), observed that of the various mulching treatments tested, leaf mulch gave the highest yield of 34.8 t/ha compared with 11.97 t/ha in the unmulched control.

Valsala et al. (1990) studied the possibility of growing daincha {Sesbania aculeata) in the interspaces of ginger beds and utilizing the green leaf material for mulching in Kerala, India. The cv. Maran was grown on raised beds (3 X 1 m with 50 cm interspaces). It was given a first mulch using locally available leaves. S. aculeata was sown in the bed interspaces immediately after planting of ginger rhizomes, it was uprooted 60 days later and used as a second mulch. It provided 4 kg green leaves per 1.5 m2, which was 50 percent of the normal requirement of 8 kg/1.5 m2. The daincha roots are also considered to be a good source of organic matter.

Pawar (1990) compared polyethylene (PE) film mulch or sugarcane trash mulch (5 t/ha), and without any mulch under Maharashtra conditions combined with different irrigation regimens (60, 80, 100, and 120 mm cumulative pan evaporimeter [CPE]). The highest yields of green ginger were obtained with the mulches and irrigation at 60 or 80 mm CPE. Under the semi-arid conditions of the trials, it was concluded that, with a PE mulch, only 50 percent less irrigation water was required to give the same yield as full irrigation.

Korla et al. (1990) conducted trials with local cv. Dharja and found that the mean yield was highest (205 to 206 g/plant) in plots mulched with grass clippings + FYM or pine needles + FYM. In Kerala, the recommended dose of mulch is 30 t/ha of green leaves applied in three splits, 15 t at the time of planting and 7.5 t each at 60 and 120 days after planting (KAU, 1993).

Kurian et al. (1997) at Vellanikkara, Kerala, India noted that green manure crops of Sesbania rostrata, S. aculeata, S. speciosa, Crotalaria juncea, or fodder cowpea (Vigna unguic-ulata), when grown amongst a ginger crop and used as the second mulch, or sown a second time 2 months after the ginger was planted and used as the third mulch, reduced weed problems in the ginger crop. The ginger rhizome yield was highest with S. aculeata used as the second mulch.

Babu and Jayachandran (1997) in Kerala, India, studied the effects of shade (0, 25, 50, or 75 percent) and mulching with leaves of Swietenia mahagoni on the yield of cv. Rio de Janeiro. Yield increased with increasing the rate of mulching. Interactions between the mulching rate and shade were observed. Under 25 percent shade, similar yields (5,256 and 5,246 kg/ha) were obtained from treatments with 100 percent (30 t/ha) and 75 percent (22.5 t/ha) of the recommended mulching rate, respectively. Gupta and Awasthi (1997) observed that in trials at Jagdalpur, India, in the kharif (monsoon) seasons of 1994 and 1995, ginger cv. Suprabha, grown with mulches of palas leaves (Butea monosperma), sal leaves (Shorea robusta), rice straw, dry grass, leaf mould, or soil, the best treatment was palas leaf mulch, which produced average fresh yield of 21.90 t/ha compared with 16.75 t/ha in the unmulched control.

E. V. Nybe and N. Mini Raj “Ginger Production in India and Other South Asian Countries” (2005)