This study was carried out in the season of 2002 and 2003 on common guava trees grown in a private orchard at EL-Noubaria (Beheira Governorate). In this study we reported four dates to start irrigation in orchard of guava. Control (mid February), (1) first date (first April), (2) second date (first May), (3) third date (first June) and (4) fourth date (first July).
These irrigation dates were chosen to obtain late crop (winter crop) without using chemical materials or workers to remove leaves. The method we are following in this study is not expensive compared to others. The fruits were held at 20-22 oC and relative humidity 75 % [control - first April - first May] and the fruits of the other dates were held at 11±2 oC and relative humidity 85-90%. The difference in room temperature due to the time of appear crops of guava. The obtained data indicated that irrigation time at 1st June and 1st July significantly decreased yield, but increased firmness, soluble solid contents, total sugars, acidity, vitamin C and phenol contents compared with irrigation times in the control and the two others (mid February and 1st of April and May).
Concerning fruits behavior held at room temperature, irrigated times at 1st June and 1st July showed a significant decrease in fruit firmness, contents of V.C, acidity and phenols and an increase in SSC, total sugars, pectin, loss in weight and decay after 7 days from picking owing to the higher temperature in summer days, fruits irrigated at early times (control, mid February and 1st April) the decay % reached about 100 % due to summer temperature. From this study the two late dates of irrigation (June and July) are very effective to obtain late crop of guava (winter crop).
The winter crop of guava fruits from trees irrigated at 1st June and 1st July are good quality and its high price covered greatly the reduce in the yield.