PROPAGATION

PROPAGATION

Limes and lemons are propagated by seed, sweet limes are raised by cuttings and layering. Pummelo, Grape fruit, Sweet orange and Mandarins are propagated by budding. Rough lemon is universally employed as a stock except in case of Mandarin for which Sweet lime stock is in common use.

For raising stock plants, seed is extracted from rough lemon which is ready for harvest in late September or early October. For extraction of seeds, tree ripe fruits are selected. They are cut into two halves

SOIL

SOIL

Deep well drained sandy, sandy loams, foams and silt or clay loarns are all suited to Citrus. However, loose open sands, or sandy foams with good physical condition are preferred. Heavy soils containing more clay are avoided, as they drain poorly and lack sufficient aeration. Citrus roots are surface feeders and hence very deep soils are not essential. They do not stand waterlogging. Citrus seems to be tolerant to slightly kalarish land, with a pH up to 8.5. The soils of middle Sind are of medium type. They contain in general clay from 22.07 to 28.93 percent and sand from 67.93 to 71.07 and are classed as Sandy foams. Hence, considered from the point of Citrus requirements, the soils in this tract are quite suitable.

CLIMATE

CLIMATE

The commercial cultivation of Citrus in the Sind area is limited to middle Sind (the districts of Hyderabad, Nawabshah and Tharparkar). The climate of this tract is quite comparable to other commercial citrus centres in the adjoining regions. In the plains of former Punjab and Frontier, citrus centres, the annual rainfall ranges from 13 to 20 inches and the relative yearly humidity from 50 to 54 percent. The highest maximum temperature is 120°F and the lowest 29°F. In the Bombay, Deccan and Khandesh sections in India, the average annual rainfall is 30 inches, the mean relative humidity 51 percent, the highest maximum temperature 110°F and the lowest minimum 36°F. Nagpur, the largest orange growing tract of India, has an annual rainfall of 44 inches and the average relative humidity 53 percent, the highest maximum temperature is I I7'F and the lowest minimum is 43°F. (Webber and Batchelor 1948). The Citrus tract of Sind _ (Vicholo Sind) has a highest maximum temperature of 110.8°F and a minimum of 47.3°F. Mean himidity is 61 percent and the annual rainfall is 7.22 inches. (Pithawala 1955).

The low temperature at which serious damage is caused to Citrus is never reached here. The area is free from prolonged cold spells (at 28°F or below) which affect adversely fruits and young shoots.

Santra, which perhaps requires a drier climate, is found to flourish in Tharusha (District Nawabshah). Though cooler weather in the northern citrus centres of West Pakistan causes unripe fruits to lose their green colour earlier compared to the Citrus centres in the Khairpur and Hyder-. abad Divisions, yet Citrus fruits are ready much earlier in these divisions if the readiness of fruits is judged from juciness in fruits and richness in flavour, due to declining acidity and increasing sugar contents. Further, cool weather seems to cause higher acidity, warmer the weather during ripening time, less acid is the fruit (Chandler 1950). Mild tropical temperature and dry period at the time of ripening seem to be well suited. Sweet oranges and grape-fruits are ready for harvest in the Hyderabad region about two months earlier and the Santras a month earlier than in the Northern Citrus centres of West Pakistan. Since the fruits in the Southern districts ripen during the warmer weather compared to the weather in the Northern districts, they remain green at the time of marketing. Blood red Malta does not develop red colour under the Sind Climate unless the winters are very severe and prolonged. However, on the whole, climatically the area is well suited to Citrus Cultivation.

CONCLUSIONS

CONCLUSIONS

There are many opportunities for increas­ing production and the percentage of marketable fruit in the Gaza Strip. For­tunately, most of the correctives have already been worked out elsewhere and need only to be adapted to local conditions. Other problems unique to the area can be solved through the guidance cf the Ministry of Agriculture.

It is a different matter, however, to say whether a further increase in citrus pro­duction is warrantable at the present time. The principal pr^-oblem facing Gaza's in­dustry is transportation. Partition left this appendage of a former territory without its traditional port facilities. At present exports are limited to the inadequate port of Gaza, where only a few ships a week make call and where vessels must anchor 500 meters offshore. At the port of Gaza, lighters cannot approach the dock closer than 15 meters, and to reach lighters, stevedores must wade waist-deep in salt water that occasionally laps at the boxes of fruit atop their heads. The government is currently considering improvement of port facilities; when these plans materialize, the expansion of Gaza's citrus industry should meet with much greater chances of success.

Before determining the causes of decline of Citrus Industry in this area, it seems necessary to review the clirtliatic and soil conditions, the cultural practices adopted and the prevalance of pests and diseases in the tract. The appraisal would help in the suggestions to be made for improvement.

NUTRITIONAL PROBLEMS

NUTRITIONAL PROBLEMS

Because of the increasing shortage of barnyard manure and the growing expansion of citrus plantings, nutritional problems are present and mily be expected to get worse. Many groves show foliar symptoms of a deficiency in zinc, iron, and manga­nese. Whenever barnyard manures are supplemented by fertilizers, the mixture consists only of nitrogen, phosphorus, and potassium. It is not known to what extent elements are tied up in the soil because of high pH values. 

APHIDS

APHIDS

Visits to the Gaza Strip took place during times when aphid populations were below peak levels nevertheless, various species were encountered on citrus. Because of in­terest in aphids as vectors of tristeza, various collections were made and prepared for identification. Toxoptera aurantii (Fonsc.) was found on Citrus sinensis and C. aurantifolia; Aphis gossypii Glov. on C. sinensis; and Aphis craccivora Koch and Myzus persicae (Sulz.) on C. paradisi.

Mediterranean fruit fly. Ceratitis capitata (Wiedemann) occurs in the Gaza Strip. While damage to fruit does not appear to be excessive, the fly does affect the time of picking. Because of increased damage to the fruit as the season progresses, all fruit must be picked by the middle of April.

Control, measures are desultory; traps are used by some growers, while others apply lindane three or four times a year.

ENTOMOLOGICAL PROBLEMS SCALES SCALES

ENTOMOLOGICAL PROBLEMS SCALES

SCALES

When trees are planted 264 to the acre, pest control obviously becomes difficult. Even at greater spacings, including the prevalent 7 X 7 meters, canopies soon join and make impossible the use of machinery in the rows. Pesticides are applied by station- ing sprayers at the edges of the groves and by "dragging garden-type hoses from the tanks to positions between the rows. In­adequate pressure and faulty coverage result in poor control; in addition, there is the custom of using 1 percent medium oils, when what obviously is needed is a 2 percent oil.

Aonidiella aurantii (Mask.) is the most prevalent scale. In recent years, it appears to have crowded out the "black" scale, Chrysomphalus aonidum (L.). Also present, but only of moderate concern, is Cero­plastes sp.

Rust mite

Present practice calls for the application of one sulfur dust annually to prevent russet. Rust mites are present, the species being Phyllocoptruta Olievora Ashm. The whole citrus-growing area is dusted between June and October. ..Control of russet is obtained in variable degrees; about 10 percent of the fruits on the local narket are russetted.

Applications of sulfur are generally made with knapsack dusters. Deposits are uneven; some leaves are -so heavily coated that appreciable quantites of sulfur persist for as long as half a year, especially during the dry summer months. Heavy residues cause further troubles when oils are later applied on top of them. Much oil-sulfur burning of the fruit was in evidence, and one of the factors responsible for the many recently killed twigs and branches in some groves, as well as the prevailing thinness of the foliage, is probably the toxic interaction of these two pesticides.

Zineb (zinc ethylene bisdithiocar-bamate), a material found in Florida to be exceedingly effective for the control of russet (2), has not been used. This material would provide better control of russet and would not damage the fruit and foliage as does oil and sulfur.