Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

AGOOtOolIC PRJ(X£TION RESEAOCH ON MAIZE IN SRI LANKA
A. Malima Perera 11
Abstract
Maize (Zea mays L.) is the second most important cereal crop in Sri Lanka. Its distribution
in the country is mainly confined to the Dry Zone where annual rainfall is less than 1200
mm/yr. The rainfall distribution in the country shows a bimodal pattern with two growing
seasons: a relatively wet season "Maha", from OCtober to February and a comparatively dry season
"Yala", from March to September.
About 85% of maize is grown under rainfed conditions and the largest amount is cultivated
on a mixed cropping system by small-scale farmers. Traditional cultivars perform poorly when
intensively cultivated under stabilized systems of highland farming. This paPer traces the
research conducted at the Regional Agric. Res. Center, Maha Illuppallama, Sri Lanka, to identify
improved varieties which could be grown under intensive management including optimum plant
densities, fertilizer use, and other improved cultural practices.
Results indicate that composite cultivars show the most promise when raised at a population
of 50,000-60,000 plants/ha and at a fertilization level of 67-45-20 kg NPK per ha during the
Maha season. In an attempt to increase the productivity of maize cultivation, a few intercropping
methods have also been developed.
Introduction
Maize is the second most important cereal crop in Sri Lanka. Its distribution in the
country is mainly confined to the Dry Zone (Fig. 1).
The rainfall distribution in the country shows a bimodal pattern with two main growing
seasons: A relatively wet season (Maha) from October to February and a comparatively dry season
(Yala) from March to September. The main climatic features of these two seasons are shown in
Table 1.
Approximately 85% of maize is grown under rainfed conditions (Maha season). Two cropping
systems are prevalent in maize cultivation, mixed cropping and monocrop.
Mixed cropping of maize is the most popular system in the country. During the dry spell
prior to "maha" rains, farmers clear thei r lands and burn the stubble. Individual land holdings
seldom exceed 1 ha. At the onset of the monsoon rains, maize is mix planted with one or two
other crops, usually grain legumes, finger millet (E7eusine coracana), mustard (Brassica nigra)
and vegetables. This system is responsible for about 85% of the total national production. The
rest comes from monoculture systems both in private and government farms.
During the last eleven years the average yield in experiments at RARe (Maha 11 1uppal lama)
is 3380 kg/ha. The yields obtained by farmers are much lower than the yields recorded at the
research center, ranging from 1100 to 1400 kg/ha.
The main reasons for the low yields are low plant densities and the limited use of high
yielding varieties and fertilizer. Low profitability of maize, high risks associated with
rainfed farming, and cost of farm resources such as labor are some of the causes for low adoption
of improved management practices by maize growers. As already stated, 90% of the farmers use
traditional varieties of maize which are tall', leafy, and late maturing. These local varieties
generally attain a height of 280-290 cm, with 18-20 leaves per plant, and mature in 130-135
days. Late maturing varieties are adversely affected when rainfall season ends earlier than
usual. But the fact that these varieties have persisted over the years suggests that rainfall
1.1 Research Officer, Regional Agri. Res. Center, Maha Illuppallama, Sri Lanka.
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