Author :N. A. Deshmukh,
Co author: R. K. Patel and Bidyut C. Deka,
Addess: Division of Horticulture, ICAR (RC) for NEH Region, Umiam-793103, Meghalaya, India

Guava (Psidium guajava L.) belongs to the family 'Myrtaceae' is native to tropical America, stretching from Mexico to Peru (Samson, 1986). It is grown practically in all the states of India and excels most of the fruit crops in productivity, hardiness, adaptability and vitamin-C content. It is moderately good source of calcium, iron and a fair source of phosphorous. In North East India, it is grown in Assam, Nagaland, Tripura, Mizoram, Sikkim and Meghalaya. It cultivation was found successfully and profitably under mid hills (upto 1000 m) altitude. In guava Allahabad Saeda and L-49 are the potential cultivars while, RCG-11, RCGH-7, RCGH-1 and RCGH-4 (developed by ICAR (RC) for NEH Region, Meghalaya) were also performed better under mid hill situation of North East India with yield potential of 35-40 kg/plant (Patel et al 2011).

Flowering behavior of guava
In guava flowers are borne only on new, succulent, vigorously emerging vegetative shoots. These new growth flushes can be either new emergences of lateral bud on older twigs or extensions of terminals shoot growth of various size and vigour. In plains of India, guava flowers two times during March-May (rainy season) and August- September (winter season). While, under mid hills altitude only one distinct flowering season i.e. April-May was observed.

Flowering dynamics in mid hills altitude
In North Eastern Region of India, during winter season i.e. December to March when the temperature and available moisture in soil is quite low creates a period of drought, which is conducive to the natural triggering of massive vegetative growth with its development of flowers and fruiting during rainy season. The consequence of these reaction to water and temperature at the critical period resulted in only one distinct guava harvest season under mid hills altitude, the April-May flowers producing fruits to mature in September and continued up to November. But the majority of fruits mature during September-October coincide with rainy season that affect the marketable yield and have poor fruit quality.

Crop regulation practices
Crop regulation is practices to harness the natural flowering and fruiting tendencies of plant to increase the yield and profitability. The production of guava fruits can be regulated by systematic cultural manipulations through pruning and defoliation of trees. Both the methods singly or in combination are found effective in delaying the flower bud formation by forcing the trees into vegetative growth. Under mid hills altitudes, spraying of ethephon 900 ppm in 30th March or defoliation of new flush during March-April were found effective practices in delaying the flowering by 20-30 days and harvesting by 25-30 days in guava. Due to this, majority of fruits are mature in mid-October to November when rain intensity was low. Thus, percentage of marketable fruits yield increased with high fruit quality. Adoption of crop regulation practices in guava had potential to extend fruit harvest season (October- November) with high fruit quality in mid hills where only one commercial crop is harvested.

References
Patel, R.K., Maiti C.S., Deka B.C., Deshmukh N.A. and Roy D. 2011. Variability studies in guava (Psidium guajava L.) genotypes for growth, yield and quality attributes at mid hills of Meghalaya. Indian J. Hill farmg. 24(1&2): 24-28.
Samson, J.A.1986. Tropical fruits. 2nd ed. Trop. Agr. Ser., Longman Scientific and Technical, New York.

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