FAQ’s

SUMMER CROPS (MAIZE, SOYA BEANS, SUGAR BEANS, SMALL GRAINS, GROUNDNUTS)

Fertilizers & Herbicides

– Prowl can be used pre-emergent for shamva grass control in the following crops,
cotton, maize, soya
– There is no pre-emergent herbicide for couch grass, however for established couch
with intact rhizomes glyphosate can be applied to clear the couch grass before
planting(therefore post emergent control of couch grass is possible with glyphosate in
non crop situations). Rates of 4lt/ha and above are recommended.
– The only pre-emergent herbicide available for nutsedge is Authority 480SC
registered for use in Soyabeans and Tobacco. However in all other cases, suppression
is possible with the chloroacetanilide groups, i.e, Lasso, Dual Magnum, Frontier
Optima, Acetochlor etc.
– The choice of herbicides is influenced by a number of factors, the most important
factor is the type of weeds to be controlled as this allows the herbicide to be matched
to the weed spectrum, other factors include, the crop involved, rotational
considerations, cost, ease of application, crop stage, size of weeds etc.

– When taking a soil sample, it must be done in a manner that largely represents the
field to be planted. If a field has got different types of soils or the same soil type but
has different crops, take the soil samples separately. Random sampling, Z-scheme or
the M scheme are some of the methods that can be used when taking a soil sample.
The best method is random sampling, avoid sampling in areas where fertilizers are
normally staked, in the field, storm drains, termite mounds and any unsightly areas of
the field being sampled.

– Depending on the crop, Lime application should be done well before planting, in
most cases at least 3months before planting. In potatoes lime should never be applied
prior to establishment rather apply the lime at some point in the rotation.

– The number of bags to be used per hectare is largely determined by soil analysis
results, yield target, cropping history, area potential and variety of crop involved.

– This will be difficult, farmers are encouraged to always use a recommended basal
fertilizer at planting. This is because phosphate is immobile in the soil and as such the
crop will not benefit from side dress applications involving phosphate once the crop is
established without this nutrient.

– The quantity ranges from 250kg-400kgs/ha, this is applied on top of the crop from
the onset of flowering, split apply for long maturing groundnut varieties.

Moisture is critical for pre-emergent herbicides as it activates the herbicide for it to
be effective. Prolonged dry spells after application of pre-emergent herbicides will
result in reduced effectiveness, in such cases lightly incorporate the herbicide using
for example spike-toothed harrows.
– Moisture is not required for most post-emergent herbicides, the most important
factor is the presence of the target weeds and these should be actively growing at the
time of application. It is important to note that rainfall or irrigation after application of
most these herbicides can reduce their effectiveness.

Insecticides & Fungicides

– Most products registered for stalk borer control in Zimbabwe are effective, but the
choice of the chemical depends on the farmer’s choice on ease of application and
affordability.

– Bean stem maggot is sprayed against on stipulated intervals, thus day 3, 6, 13 and 20
after the emergence of the bean crop. The most effective way however is to seed dress
with Apron star before planting.

– Soya bean rust can be controlled by spraying a number of recommended fungicides
from day 50-70 after crop emergence. Normally spray from the onset of flowering.

– When planting maize out of season Maize Streak Virus is the biggest challenge,
always seed dress with Gaucho or Cruiser. The products will help control leaf hoppers
which are the main vectors of the virus in maize. Incidence of MSV is very high in
areas where irrigated pastures and or wheat are grown. A number of new varieties
with improved tolerance to MSV are coming into the market. It is best to check with
your seed supplier.

– Regent and Imidachloprid 200SL/350SC are registered for control of termites in
maize. The two products are applied prior to termite attacks, Regent is applied at
planting and can be combined with most pre-emergent herbicides while Imidachloprid
is applied 8-10 weeks after crop emergence prior to termite attacks.

– Witchweed(Striga spp.) chemical control using herbicides is very difficult in maize.
By nature, witchweed is parasitic, i.e. it attaches itself to the host plant through a
structure called haustorium and begins to draw nutrients from the affected maize
plant, most of this damage occurs before the witchweed emerges above the ground.
Thus makes it difficult for most herbicides to control the weed during this stage.
While it emerges above the ground later and products such Stella star can be used, this
is usually too late for effective results. Management of this problem involves the
combined use of cultural practices, rotate with legume crops e.g cowpeas and or apply
manure, optimal nitrogen fertilization can also help.

– Actellic gold Dust exclusively distributed by ZFC limited, it is available in most
retail outlets.

HORTICULTURE CROPS

Fertilizers & Herbicides

– Most crops broadly fall into two categories, that is the warm season crops and cool
season crops. Most warm season crops will not do well in winter and most of them
succumb to frost injury making it difficult for winter production e.g, maize tomatoes,
pepper etc

– ZFC has got a wide range of fertilizers, for the basal fertilizers, one can use
Vegetable blend (9:24:20), Compound C (5:15:12), Compound S (7:21:8) and for the
top dressing fertilizers apply Ammonium Nitrate, Potassium Nitrate, SOP/MOP,
Calcium Nitrate, Potato super top (23:0:24). The importance of trace elements in
horticulture cannot be overemphasized and ZFC manufactures the following
speciality fertilizers for the supply of trace elements, Quick start plus, Quick grow
plus, Best bloom plus, Foliar 15 and Foliar feed for use in horticultural crops.

– Foliar fertilizers improve the quality of horticultural crops as they supply the
necessary trace elements which neither the soil nor the main fertilizer program can
adequately supply. The yield aspect is largely driven by the effective use of the basal
and top dressing fertilizers to meet the nutrient guideline per crop as well as other
aspects of crop management.

– Very few herbicides are registered for use in horticulture, herbicides such as Lasso,
Dual, Goal, Fusilade, Paraquat and Glyphosate(Round Up) are frequently used
however. It is important to ensure the product is registered in the particular crop for
which one intends to use it otherwise serious crop damage occurs.

– Compound D (Maizefert) should not be used in tomatoes because they contain a
marked percentage of Chlorine which tends to hamper the growth of tomatoes
resulting in low yields.

– The best time to apply basal fertilizers is always before or at planting.

Insecticides & Growth Regulators

– Rhizobium inoculation helps the plant fix nitrogen with the result that for the
nitrogen requirement very little or no nitrogen top dressing fertilisers are required.
Basal fertiliser is still required in all cases.

– Depending on the unit area to be covered, non fumigants such as Solvigo and
Fenamiphos are cost effective while Basamid or Metham sodium can be used as
fumigants.

– To control cutworms, one can drench or spray Lambda cyhalothrin, Chlopyriphos
and Fenvalerate, Decis forte, Carbaryl onto the base of the horticultural crops. This
treatment should be done within a week after either transplanting or emergence of the
crops.

– Rhizobium inoculation helps the plant fix nitrogen with the result that for the
nitrogen requirement very little or no nitrogen top dressing fertilisers are required.
Basal fertiliser is still required in all cases.

– Horticultural crops are susceptible to different insect pests. These pests range from
their larval to their adult stages and these include the leaf miners, leaf hoppers,
diamond back moth, aphids, red spider mite, white fly, thrips, tuber moth, bollworms,
cutworms etc.

Fungicides

– Fungicides can be classified into preventative and curative. It is important however
that when an infection has taken place, curative fungicides be used to control the
infection. A combination of both groups of fungicides is usually employed to avert
crop losses.

– There are several causes for plants to wilt. However, it is critical that each case be
diagnosed such that the most appropriate remedy is advised.
– Which chemicals are best for powdery & downey mildew control in cucurbits?
– The best chemicals to use for powdery mildew in cucurbits is Benomyl (Benlate),
Folicur. Use Ridomil gold for Downey mildew.

– One of the reasons for the cracking of tomatoes could be inconsistencies in irrigation
regimes. Rolled leaves could possibly be a viral infection, unfortunately it has no
cure. Leaf roll can also be caused by environmental conditions mostly cold
temperatures. The pattern should normally be used to diganose the environmental
condition involved.

CASH CROPS

Tobacco Seedbeds

– Tobacco Seedbedfert (7:21:8) can be used for tobacco seedbeds. The general
recommendation for a 36 m2 seed bed ranges between 3 to 6 kg.

– It is preferable to use calcium nitrate to top dress tobacco seedbeds as its use does
not complicate hardening processes. It usually results in a much quicker response
than AN.

– The herbicides that can be used in tobacco seedbeds are Clomazone 4 EC (pre-
emergent)-usually at sowing and Fusilade forte or Agil post emergence.

– Most nematicides are used at least 2 weeks in advance of seedbed establishment.

– Thunder, Decis forte, Confidor, Actara can be used in place of the phased out
products.

– Alternaria leaf spots can be managed by use of preventative fungicides such as
Bravo, Copper, Mancozeb, Antracol. Bion can also be used for an activated response
before infection.

Tobacco Lands

Use Folicur, Score, Nativo, Amistar top to control Alternaria and Frog eye leaf spots
in tobacco. Always use Bion at 5-7 and 8-9weeks in the lands.

– Choice will depend among other things cost and availability of trace elements in the
fertiliser, but factors such as separation of blends should be considered if transporting
the product over long distances.

– It improves quality by maintaining leaf integrity, resulting in a much stronger leaf
with resistance to shattering, this results in very low levels of trash.

– Depends on a lot of factors, e.g soil type, residual fertiliser, amount of rainfall
received etc, a 3.5te/ha crop normally requires 80units of Nitrogen supplied from both
the Basal and Nitrogen top dressing. Usually 150-200kg/ha of AN will do.

Sukerkil (N-Decanol) 4lt/100lt water and Accotab 1.5lt/100lt, Apply using either cup
8 or cup 12 per plant to cover all leaf axils without excess runoff into the soil. Always
read the label first!