Protected Cultivation Questions and Answers

Answer: D

The key gives eyes cutting: in protected cultivation, grape can be propagated by single-eye cuttings, in which a cutting with one bud is rooted in a medium under controlled humidity and warmth. I could not find a source comparing the other methods, so this rests on the key.

Budding, cleft grafting and epicotyl wood grafting are used for grafting onto rootstocks, not for propagation in this way.

Answer: B

Parthenocarpic varieties are suitable for protected cultivation of cucumber. They set fruit without pollination, which suits a polyhouse where there are no bees, and the fruits are seedless.

Hermaphrodite, monoecious and andromonoecious types need pollination or give a lower yield of seeded fruit in the protected structure.

A parthenocarpic cucumber sets fruit without pollination, and the fruit is seedless, which is needed because there are no pollinating insects inside the polyhouse. Such cultivars are usually all-female.

Answer: B

The plastic film greenhouse is the type that is not classified on the basis of shape: it is named after its covering material. Quonset, ridge-and-furrow and saw-tooth houses are named for their shape and roof form.

Greenhouses are classified by shape (Quonset, ridge and furrow, saw tooth), by the covering material (glass, plastic film) and by the use. Plastic film names the covering and not the shape.

Answer: C

Topping is an essential operation for the tomato crop in a greenhouse. The growing tip of the indeterminate plant is pinched off after the planned number of trusses, which stops height growth and sends food to the fruits.

Brinjal, chilli and capsicum are pruned in other ways, and the key does not name them for topping.

Answer: D

Anthurium needs about 80 per cent shade in summer.

Anthurium is a shade-loving tropical plant. Direct sunlight scorches its leaves and fades the spathes, so it is grown under shade nets that cut out about 75-80% of the light, the higher level in summer when the sun is strongest. Too much shade, on the other hand, gives weak plants and few flowers.

Shade of only 50-70% lets in too much summer light for anthurium, though such levels suit sun-tolerant cut flowers.

Answer: B

The cladding is usually 200 micron thick.

Greenhouses in India are commonly covered with UV-stabilised low-density polyethylene film of 200 micron (800 gauge). UV stabilisation stops the film from becoming brittle in sunlight, and at 200 micron it lasts about three years while transmitting enough light for crops.

Thinner film of 100 micron tears easily and degrades quickly, and thicker films of 250-300 micron cost more and cut light without a matching benefit, so 200 micron is the standard specification.